Home laundering allows for the treatment of fabrics with a variety of materials which impart some desirable benefit or quality to the fabrics during the laundering. At each stage of the laundering operation, i.e., pre-soaking, washing, rinsing and drying, the fabrics are to a varying degree found in contact with water which can provide a medium for the delivery of a fabric-conditioning agent or agents. Delivery of the fabric-conditioning agent(s) to the fabrics, however, is not without certain difficulties.
Fabric conditioning in a home laundry is usually achieved by adding a liquid solution containing a fabric conditioner and, optionally, a dispersing agent to an automatic washing machine during the rinse cycle of the machine. Addition of the conditioner during the rinse cycle, rather than at the initiation of the wash cycle, is often required due to the chemical incompatibility of certain conditioning agents with the detergents used to launder the fabrics. Since the conditioner has to be added during the rinse cycle in order to be effective, the washing machine has to be monitored to determine when the rinse cycle begins. This makes the process of adding the conditioner inconvenient and time-consuming.
Various methods and devices have been utilized to improve the efficiency of applying a fabric conditioner to fabrics during the home laundering operation. Examples of relevant devices and methods of use are as follows:
U.S. Pat. Nos. 4,026,131 and 4,260,054 are directed to laundry additive dispensers or pouches for automatically introducing a laundry additive into the rinse water in automatic clothes washers. According to these patents, the dispenser or pouch is suitably attached to the central post of an agitator of an automatic clothes washer at the beginning of the wash cycle. The pouch contains a rupturable fold or weakened area, such as a slit, in the wall of the pouch whereby during the spin cycle immediately before the rinse cycle the rupturable fold or weakened area in the wall of the pouch will rupture and open, allowing the release of the contents of the pouch into the washer during the rinse cycle.
U.S. Pat. No. 4,356,099 (corresponding to European No. 0 040 931) discloses a fabric treatment product for use in a washing machine consisting of a bag formed of water-insoluble, water-impermeable synthetic plastic sheet material containing a fabric treatment composition, such as a detergent combination, in liquid form. The bag has a weak seal accomplished, for example, by inserting a non-woven fabric between the opposed bag walls of thermoplastic materials, and then heat-sealing to provide a weak seal. According to the patent, the weakened seal will cause the package to open during the first few minutes of the wash cycle of the washing machine operation. The release is not delayed for use in the rinse cycle.
U.S. Pat. No. 4,108,600 discloses a fabric conditioning article comprising a receptacle releasably containing a pH control agent or electrolyte and fabric-conditioning particles having a coating which is made indispersible by the pH control agent or electrolyte. The fabric-conditioning article is placed in a clothes washer at the beginning of the wash cycle. The receptacle has at least a part of one wall made of a water-insoluble porous material to allow for the release of the pH control agent or electrolyte during the wash cycle. The pH control agent or electrolyte causes the particle coating on the fabric conditioner to gel or precipitate and become water-insoluble. Once the electrolyte or pH control level drops below the gelling level, the particle coating begins to dissolve and disperse thereby releasing the fabric conditioner into the surrounding area. Preferably the fabric conditioner is not released until the washer rinse cycle or the drying cycle of a clothes dryer. The fabric-conditioning article disclosed in the U.S. Pat. No. 4,108,600 requires the use of an outer receptacle and a coating on the fabric-conditioning particles. Additionally, the use of an electrolyte or pH control agent to control the dispersibility of the fabric-conditioning agent is required.
U.S. Pat. No. 4,082,678 discloses a fabric conditioning article having a two-receptacle pouch and containing an electrolyte, pH control agent, and fabric softener. The U.S. Pat. No. 4,082,678 is similar in mechanism to the U.S. Pat. No. 4,108,600 discussed above. The difference is in the utilization of an inner receptacle for the fabric conditioner as opposed to a coating on the conditioner particles. At least a part of one wall of the outer receptacle is water-soluble or dispersible. The inner receptacle wall is made insoluble by the electrolyte and pH agent. Cellulose derivatives are disclosed as suitable materials for making the outer and inner receptacles. As with the U.S. Pat. No. 4,108,600 discussed above, the use of an electrolyte or pH agent to control the dispersibility of the fabric conditioner is required.
U.S. Pat. No. 4,304,562 discloses a fabric softener article added to a washer at the beginning of the wash cycle and having a delayed release, i.e., at the end of the wash cycle or the beginning of the rinse cycle. The softener containing article is a block of porous felt, cloth or foam, with fabric conditioner impregnated into an area of the block and with release being delayed until some time after the beginning of the wash cycle of the washing machine.
U.S. Pat. No. 4,203,851 discloses a free-flowing particulate fabric softening composition comprising a base bead impregnated with a fabric softener which is usable in a washer. The base bead can contain a waxy material to prevent premature reaction of the softener with anionic materials, or slow the rate of release of the softener so that less softener reacts with the anionic detergent. The base bead is composed of a builder such as zeolite or silicate.
U.S. Pat. Nos. 4,115,292; 3,186,869, and 3,322,674 disclose packages of water-soluble material, such as cellulose or cellulose derivatives, containing a material to be dispersed, such as a detergent or bleach. The '292 patent also discloses that starch or polyacrylics can be utilized as the water-soluble material of the package. Each of the packages disclosed in the above patents, however, is disclosed as being readily water-dissolvable and do not provide for the delayed release of the material contained within the package.
The prior art does not disclose a fabric conditioner containing package which can be added to the washing machine along with the fabrics, such as clothes, being washed and the detergent to effect cleaning at the beginning of the wash cycle of a conventional automatic washer and which does not release the fabric conditioner until the wash cycle is completed or the rinse cycle has begun.